Chilkat HOME .NET Core C# Android™ AutoIt C C# C++ Chilkat2-Python CkPython Classic ASP DataFlex Delphi ActiveX Delphi DLL Go Java Lianja Mono C# Node.js Objective-C PHP ActiveX PHP Extension Perl PowerBuilder PowerShell PureBasic Ruby SQL Server Swift 2 Swift 3,4,5... Tcl Unicode C Unicode C++ VB.NET VBScript Visual Basic 6.0 Visual FoxPro Xojo Plugin
(VB.NET) Sign PDF: Choosing RSASSA-PSS or PKCS1-v1_5 and Hash AlgorithmSee more PDF Signatures ExamplesThis example demonstrates how to choose between RSASSA-PSS vs. PKCS1-v1_5 and the hash algorithm when signing a PDF.
' This example requires the Chilkat API to have been previously unlocked. ' See Global Unlock Sample for sample code. Dim pdf As New Chilkat.Pdf ' Load a PDF to be signed. ' The "hello.pdf" is available at https://chilkatsoft.com/hello.pdf Dim success As Boolean = pdf.LoadFile("qa_data/pdf/hello.pdf") If (success = False) Then Debug.WriteLine(pdf.LastErrorText) Exit Sub End If ' Options for signing are specified in JSON. Dim json As New Chilkat.JsonObject ' In most cases, the signingCertificateV2 attribute is needed. json.UpdateInt("signingCertificateV2",1) ' --------------------------------------------------------------------------------------------------------------------------- ' This example is the same as the example at Sign a PDF (Simplest Example Possible) ' but with the following lines added to specify the signature scheme and hash algorithm. ' The signature schemes PKCS-v1_5 and RSASSA-PSS have differences. ' PKCSV1_5 is deterministic. The same message and key will produce an identical signature value each time. ' PSS is randomized and will produce a different signature value each time. ' To choose the hash algorithm: ' (The typical choices are sha1, sha256, sha384, and sha512.) json.UpdateString("hashAlgorithm","sha256") ' To choose PKCSV1_5: json.UpdateString("signingAlgorithm","pkcs") ' Alternatively, to choose RSASSA-PSS: json.UpdateString("signingAlgorithm","pss") ' If not specified, the default is SHA256 with PKCS-v1_5. ' The remainder of this example is the same as the example at Sign a PDF (Simplest Example Possible) ' --------------------------------------------------------------------------------------------------------------------------- ' Put the signature on page 1, top left json.UpdateInt("page",1) json.UpdateString("appearance.y","top") json.UpdateString("appearance.x","left") ' Use a font scale of 10.0 json.UpdateString("appearance.fontScale","10.0") ' In this example, the appearance of the digital signature will contain three lines: ' 1) The signing certificate's common name ' 2) The current date/time ' 3) Some arbitrary text. ' The keyword "cert_cn" is replaced with the Certificate's Subject Common Name. ' The keyword "current_dt" is replaced with the current date/time. ' Any number of appearance text lines can be added. json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn") json.UpdateString("appearance.text[1]","current_dt") json.UpdateString("appearance.text[2]","The crazy brown fox jumps over the lazy dog.") ' Load the signing certificate. (Use your own certificate.) Dim cert As New Chilkat.Cert success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret") If (success = False) Then Debug.WriteLine(cert.LastErrorText) Exit Sub End If ' Tell the pdf object to use the certificate for signing. success = pdf.SetSigningCert(cert) If (success = False) Then Debug.WriteLine(pdf.LastErrorText) Exit Sub End If success = pdf.SignPdf(json,"qa_output/hello_signed.pdf") If (success = False) Then Debug.WriteLine(pdf.LastErrorText) Exit Sub End If Debug.WriteLine("The PDF has been successfully cryptographically signed.") ' The appearance of the signature appears in Adobe Acrobat as shown here: |
© 2000-2024 Chilkat Software, Inc. All Rights Reserved.